Call you cell phone and leave yourself another message. Then call your
voicemail with your cell phone and retrieve the messages as normal,
Press 7 to delete each message. Once you are done be sure to use the *
key to exit your voice mail. Once it disconnects watch the display and
the message waiting indicator will clear itself.

I tried that first but it didn't help. It wasn't fixed until the next
morning. Did you read my above response?